There's no functional difference between the two. If you do see a difference, it's likely because Google rotates datacenters every 5 mins. So you might have caught two datacenters out of sync.

I'd be interested to know where you got that time frame from? You're right in saying that people could be chance see different results due to seeing results from different data centers that haven't updated at the same time (this is more likely to happen when checking rankings across different browsers rather the changing between http and https secure search), but every 5min, where did you read that?

I'd be interested to know where you got that time frame from? You're right in saying that people could be chance see different results due to seeing results from different data centers that haven't updated at the same time (this is more likely to happen when checking rankings across different browsers rather the changing between http and https secure search), but every 5min, where did you read that?

I'm not sure it's 5 mins anymore. It seems like it might be less in some cases. But I didn't read it anywhere, I found it when doing a raw DNS lookup on Google

;; ANSWER SECTION:
google.com. 190 IN A 74.125.228.104
google.com. 190 IN A 74.125.228.105
google.com. 190 IN A 74.125.228.110
google.com. 190 IN A 74.125.228.96
google.com. 190 IN A 74.125.228.97
google.com. 190 IN A 74.125.228.98
google.com. 190 IN A 74.125.228.99
google.com. 190 IN A 74.125.228.100
google.com. 190 IN A 74.125.228.101
google.com. 190 IN A 74.125.228.102
google.com. 190 IN A 74.125.228.103

See that column that says 190? That's called the Time To Live(TTL). It lets you know how long this result is good for, in seconds. Google uses a variant of round robin DNS where that long list of A records changes when that TTL expires. I ran a few just to see if I would get any 300s(5 min) and I got a 261 but once it rolled over and gave me 30 secs. But 5 mins is probably still the default. They've been doing this for years and it's transparent because you never know when your browser is doing a brand new DNS lookup.

Most sites have a TTL of 86400 (1 day) because you don't want your DNS servers hammered all the time and your A records (where you get the IP) don't change that often.

Originally Posted by nithin

i am not believing in that google rotates data centers every 5 mints. if that happens, result will change in every 5 mints. is it happens????

Lest you misunderstand me, I'm NOT saying that RESULTS change every 5 mins. But you WILL change datacenters every 5 mins, if not sooner. What I am saying is that it's possible that you hit DC1 and got result A on HTTP. Then you did the same thing on HTTPS but now you're hitting DC2. It's possible DC2 was slightly out of sync in the network and fed you a different result. Or maybe it was vice versa. Whatever the case, Google has to distribute things like the index, algorithm, etc. It's possible that they were not in sync. It's uncommon but it happens.

In theory,it's the same.'https' is just a secure transfer protocol. but google will record your search behavior and habits,so the ranking may change by artificial.
If you don't want this happen,use ths addressGoogle) ,it will not record the user search behavior.